Substrate structure having chamfers

ABSTRACT

Provided is a substrate structure, including a substrate having at least one chamfer formed on a surface thereof, and a plurality of conductive bodies formed to the substrate. Therefore, a stress generated during the packaging process is alleviated through the chamfer, and the substrate structure is prevented from being cracked. An electronic package employing the substrate structure is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims under 35 U.S.C. § 119(a) the benefit ofTaiwanese Patent Application No. 105112802 filed Apr. 25, 2016, theentire contents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to semiconductor packages, and, moreparticularly, to an electronic package that has improved product yieldand a substrate structure thereof.

2. Description of Related Art

There are numerous techniques used in chip packaging, including flipchip packaging, such as Chip Scale Package (CSP), Direct Chip Attached(DCA) and Multi-Chip Module (MCM), and 3D IC chip stacked modules thatstack chips in a three-dimensional manner.

FIG. 1 is a schematic cross-sectional view of a conventionalsemiconductor package 1 in the 3D IC form. The semiconductor chip 13 isprovided on a Through Silicon Interposer (TSI) 12 via a plurality ofsolder bumps 130. The TSI 12 has a plurality of Through Silicon Vias(TSVs) 120 and a redistribution layer (RDL) 121 electrically connectingthe TSVs 120 and the solder bumps 130, and is formed onto a packagesubstrate 11 via the TSVs 120 and a plurality of conductive elements110. The conductive elements 110 and the solder bumps 130 areencapsulated with an underfill 10′, and the semiconductor chip 13 andthe TSI 12 is encapsulated by an encapsulant 10.

However, in the traditional packaging process of the semiconductorpackage 1, when temperature cycle or stress variation is encountered,large corner stress may be created at the corners of the semiconductorchip 13 and the TSI 12, causing cracks (such as cracks K in the diagram)to appear around the corners of the semiconductor chip 13 and the TSI12. In addition, mismatch in coefficients of thermal expansion betweenthe semiconductor wafer 13, the TSI 12 and the package substrate 11 maycause the encapsulant 10 or the underfill 10′ to be detached, creatingdelamination. As such, the TSI 12 cannot be effectively connected to thesemiconductor chip 13 or even leads to failures in reliability tests,resulting in poor product yield. The aforementioned problems become moreprominent in today's quest for ever thinner and more compact electronicproducts.

Therefore, there is an urgent need to find a solution that overcomes theaforementioned problems in the prior art.

SUMMARY

In view of the foregoing shortcomings in the prior art, the presentdisclosure provides a substrate structure, which may include a substrateincluding at least one first chamfer formed on a surface thereof and asecond chamfer extending from the first chamfer; and a plurality ofconductive bodies formed to the substrate.

The present disclosure further provides an electronic package, which mayinclude a carrier; at least one substrate disposed on the carrier and atleast one first chamfer formed on a surface of the substrate; aplurality of conductive bodies electrically connected to the substrateand the carrier; and an encapsulating material formed between thesubstrate and the carrier.

In an embodiment, the encapsulating material encapsulates the substrate.

In an embodiment, the first chamfer is provided at a corner of thesubstrate.

In an embodiment, the surface of the substrate may be further formedwith a recess free from penetrating the substrate. In anotherembodiment, the first chamfer and the recess may be spaced apart at adistance, and the recess may be provided at a corner of the substrate.In yet another embodiment, the recess may have a large opening width anda small inner space width, or a small opening width and a large innerspace width.

In an embodiment, at least one of the conductive bodies is a circuitlayer, a conductive pillar or a conductive bump.

In summary, the electronic package and the substrate structure inaccordance with the present disclosure alleviate stress on the substratethrough the first chamfer, and increase bonding between the substrateand the packaging layer with the provision of the recess, therebyeliminating the occurrences of cracks and delamination of the substrateduring the packaging process and increasing the product yield.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a conventionalsemiconductor package;

FIG. 2 is a schematic cross-sectional view of a substrate structure inaccordance with the present disclosure;

FIGS. 3, 3′, 3″, and 3″′ are schematic cross-sectional views of anotherembodiment of FIG. 2;

FIG. 4 is a schematic cross-sectional view of recesses in various shapesof a substrate structure in accordance with the present disclosure;

FIGS. 5A to 5F are schematic top views of different embodiments of asubstrate structure in accordance with the present disclosure; and

FIG. 6 is a schematic cross-sectional view of an electronic package inaccordance with the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The present disclosure is described by the following specificembodiments. Those with ordinary skills in the arts can readilyunderstand other advantages and functions of the present disclosureafter reading the disclosure of this specification. The presentdisclosure may also be practiced or applied with other differentimplementations. Based on different contexts and applications, thevarious details in this specification can be modified and changedwithout departing from the spirit of the present disclosure.

It should be noted that the structures, ratios, sizes shown in thedrawings appended to this specification are to be construed inconjunction with the disclosure of this specification in order tofacilitate understanding of those skilled in the art. They are notmeant, in any ways, to limit the implementations of the presentdisclosure, and therefore have no substantial technical meaning. Withoutaffecting the effects created and objectives achieved by the presentdisclosure, any modifications, changes or adjustments to the structures,ratio relationships or sizes, are to be construed as fall within therange covered by the technical contents disclosed herein. Meanwhile,terms, such as “up”, “first”, “second”, “third”, “a”, “one” and thelike, are for illustrative purposes only, and are not meant to limit therange implementable by the present disclosure. Any changes oradjustments made to their relative relationships, without modifying thesubstantial technical contents, are also to be construed as within therange implementable by the present disclosure.

FIG. 2 is a schematic cross-sectional view of a substrate structure 2 inaccordance with the present disclosure. The substrate structure 2includes a substrate 21 including at least one chamfer 210 formed on itssurface, and a plurality of conductive bodies 25 formed to the substrate21.

The substrate 21 can be a semiconductor material, and the first chamfer210 is formed on an edge (e.g., a corner) of a surface 21 a thereof.However, the substrate 21 can be made of, but not limited to, a ceramicmaterial or an organic material, such as a glass fibre resin or aprinted circuit board.

In an embodiment, the substrate 21 can be a silicon wafer, a siliconchip or a Through-Silicon Interposer (TSI) and can be in the form of astrip or singulated, and the first chamfer 210 is formed by cutting thesubstrate 21 with a trapezoidal knife.

Furthermore, the substrate 21 can be a board in any geometric shape,such as rectangle, polygon, circle, etc., and can be a symmetrical ornonsymmetrical board. Therefore, the substrate 21 may assume a varietyof different appearances. Moreover, the surface of the first angle 210may have a straight oblique face (such as that shown in FIG. 6), aconcave arc face (such as those shown in FIGS. 2 and 3), a convex arcface (such as that shown in FIG. 3′), or other shapes.

The conductive bodies 25 can be selected from a group consisting of acircuit layer (not shown), conductive pillars and conductive bumps (suchas those shown in FIG. 2).

In an embodiment, each of the conductive bodies 25 includes a metalpillar 25 a and a solder material 25 b.

In another embodiment, as shown in FIGS. 3 and 3′, the substratestructure 3 further includes a seal ring 31 provided on the surface 21 aof the substrate 21. The seal ring 31 surrounds a layout area A of thesubstrate 21 (an area for laying out the conductive bodies 25), and atleast one recess 34 not penetrating the substrate 21 is provided outsidethe seal ring 31 on the surface 21 a of the substrate 21. The firstangle 210 and the recess 34 are spaced apart at distance L. In otherwords, the recess 34 is situated between the first angle 210 and theseal ring 31 to prevent the cutting tool from touching the conductivebodies 25. This effectively prevents the metal material from shrinkingand covering the cutting tool as a result of the cutting).

More specifically, there are numerous ways for manufacturing the recess34, including ultrasonic polishing, chemical mechanical polishing (CMP),laser, water knife, isotropic/anisotropic etching, dry/wet etching or acombination of the above. Moreover, as shown in FIG. 4, the shape andsize of the recess 34, 34′, 34″ may vary depending on the type ofmaterial used as an encapsulating material 60 shown in FIG. 6. In otherwords, the aspect ratio of the recess 34 allows the particles of theencapsulant to enter therein with no hindrance. For example, the maximumsize of a particle in a filler contained in an existing encapsulant 6 is3 μm, then the recess 34, 34′, 34″ has an opening width R greater than 3μm (e.g., 10 μm) and a depth D about 3 to 6 μm. Therefore, the openingwidth R of the recess 34, 34′, 34″ needs to be greater than the particlesize of the filler of the encapsulating material 60.

In addition, the recess 34 may assume various different appearances. Asshown in FIG. 4, for example, the cross sections of the recesses 34,34′, 34″ are cave-like with a plurality of sidewalls. Moreover, as shownin FIGS. 5A to 5F, the top view of the recess 34 may have any geometricshape (an arc, a polygonal, a circular shape or etc.). Morespecifically, as shown in FIG. 4, if the recess 34 has a large openingwidth and a small inner space width, and the fluidity of theencapsulating material 60 in the recess 34 is increased; alternatively,if the recess 34′ has a small opening width and a large inner spacewidth, bonding between the encapsulating material 60 and the recess 34′(that is, the encapsulating material 60 and the substrate 21) isincreased. It should be understood that the widths of the opening andthe inner space of the recess 34″ can be the same.

In addition, the location of the recess 34 can be designed according todemands. For example, the recess 34 can be provided at areas of thesubstrate 21 where stress is concentrated during manufacturing of thesubstrate structure 3 to prevent cracks occurring in the substrate 21and delamination of the encapsulating layer (e.g., an underfill 600 oran encapsulant 601, as will be described later). More specifically, asshown in FIGS. 5A to 5E, if the surface 21 a of the substrate 21 hascorners, during the packaging process, corner stress will occur at thevarious corners of the substrate 21 due to concentrated stress, andlarge stress is created between the corners and the encapsulatingmaterial 60, thus a recess 34 can be located at each of these corners.

In another embodiment, as shown in FIGS. 3 and 3′, the substrate 21 hasa second chamfer 310 extending from the first chamfer 210. In anembodiment, the second chamfer 310 extends along a side face 21 c of thesubstrate 21, and the surface of the second chamfer 310 may be astraight face, an arc face, or some other shapes.

In another embodiment, as shown in FIGS. 3″ and 3′″, the substrate 21further has a third chamfer 311 and a fourth chamfer 312 (or even moreangles) extending from the second chamfer 310 sequentially, so as toreduce stress through increasing the numbers of chamfers. In addition,the surfaces of the chamfers may be, but not limited to, a straightface, a convexed or concaved arc face, or some other shapes, which arearranged appropriately.

In an embodiment, the substrate structure 3 further comprises chamfersextending from the second chamfer 310 sequentially. In anotherembodiment, the substrate structure 3 further comprises at least onechamfer extending in a direction different from another direction inwhich the second chamfer 310 extends from the first chamfer 210 and/oryet another direction in which the first chamfer 210 extends from thesurface 21 a of the substrate 21. In an embodiment, the third chamfer311 extends from the second chamfer 310, and the fourth chamfer 312extends from the third chamfer 311. In an embodiment, the substratestructure 3 further comprises a plurality of chamfers extendingsequentially from the second chamfer 310 and forming an approximatelystraight line.

The substrate structure 2, 3 according to the present disclosure allowsstress on the substrate structure 2, 3 created during the subsequentpackaging process to be distributed through the design of the firstchamfer 210, eliminating the issue of stress being concentrated at thecorners of the substrate structure 2, 3, and preventing cracks ordelamination from occurring in the substrate structure 2, 3 afterpackaging, thereby increasing the product yield.

In addition, with the design of the second chamfer 310, the substratestructure 3 achieves even better stress elimination.

FIG. 6 is a schematic cross-sectional view of an electronic package 6 inaccordance with the present disclosure. As shown in FIG. 6, theelectronic package 6 includes a carrier 63, a first substrate 61, asecond substrate 62 disposed on the carrier 63, and an encapsulatingmaterial 60.

The carrier 63 can be made of a ceramic or organic material used as apackage substrate, and the first substrate 61 and the second substrate62 are made of semiconductor materials. The second substrate 62 is usedas an interposer and is placed directly on the carrier 63, while thefirst substrate 61 is used as an electronic element and is placeddirectly on the second substrate 62.

In an embodiment, the first substrate 61 (e.g., the electronic element)is an active element such as a semiconductor chip, a passive element,such as a resistor, a capacitor and an inductor, or a combination ofboth.

In an embodiment, the first substrate 61 (e.g., the electronic element)can be directly placed on the carrier (e.g., the package substrate),without the intermediate second substrate 62 (e.g., a TSI).

Moreover, the first chamfer 210 can be optionally formed on the firstsubstrate 61 and/or the second substrate 62, and the seal ring 31, therecess 34 and/or the second chamfer 310 can be optionally formed on thefirst substrate 61 and/or the second substrate 62 as shown in FIGS. 3and 3′.

The conductive bodies 25 are formed to the first substrate 61 and thesecond substrate 62 for electrically connecting the first substrate 61,the second substrate 62 and the carrier 63.

The encapsulating material 60 is formed on the carrier 63 to encapsulatethe first substrate 61 and the second substrate 62.

In an embodiment, the encapsulating material 60 includes an underfill600 and an encapsulant 601. The underfill 600 is formed between thefirst substrate 61 and the second substrate 62 and between the secondsubstrate 62 and the carrier 63, and the encapsulant 601 is formed onthe carrier 63 to encapsulate the underfill 600, the first substrate 61and the second substrate 62.

The electronic package 6 according to the present disclosure allowsstress on the first substrate 61 and the second substrate 62 createdduring formation of the encapsulating material 60 to be distributedthrough the design of the first chamfer 210, eliminating the issue ofstress being concentrated at the corners of the first substrate 61 andthe second substrate 62, and preventing cracks and/or delamination fromoccurring in the first substrate 61 and the second substrate 62 duringthe packaging process, thereby increasing the product yield.

In summary, the electronic package and the substrate structure inaccordance with the present disclosure alleviate stress concentrationand thus increase the product yield through the provision of chamfers.

The above embodiments are only used to illustrate the principles of thepresent disclosure, and should not be construed as to limit the presentdisclosure in any way. The above embodiments can be modified by thosewith ordinary skill in the art without departing from the scope of thepresent disclosure as defined in the following appended claims.

What is claimed is:
 1. A substrate structure, comprising: a substrateincluding at least one first chamfer formed on a surface thereof, asecond chamfer extending from the first chamfer, and a third chamferextending from the second chamfer in a first direction different from asecond direction in which the second chamfer extends from the firstchamfer, wherein the first chamfer, the second chamfer, and the thirdchamfer are not perpendicular to the surface, and the first chamfer isinclined relative to the surface; and a plurality of conductive bodiesformed to the surface of the substrate.
 2. The substrate structure ofclaim 1, wherein the first chamfer is provided at a corner of thesubstrate.
 3. The substrate structure of claim 1, further comprising arecess formed on the surface of the substrate with the recess free frompenetrating the substrate.
 4. The substrate structure of claim 3,wherein the first chamfer and the recess are spaced apart at a distance.5. The substrate structure of claim 3, wherein the recess is provided ata corner of the substrate.
 6. The substrate structure of claim 3,wherein the recess has an opening width and an inner space width lessthan the opening width.
 7. The substrate structure of claim 3, whereinthe recess has an opening width and an inner space width greater thanthe opening width.
 8. The substrate structure of claim 1, wherein atleast one of the conductive bodies is a circuit layer, a conductivepillar or a conductive bump.
 9. The substrate structure of claim 1,wherein the substrate further comprises a fourth chamfer, the third andfourth chamfers extending from the second chamfer sequentially.
 10. Thesubstrate structure of claim 1, wherein the substrate further comprisesa fourth chamfer extending from the third chamfer.
 11. The substratestructure of claim 1, wherein the substrate further comprises a fourthchamfer, the third and fourth chamfers extending sequentially from thesecond chamfer and forming an approximately straight line.
 12. Thesubstrate structure of claim 1, wherein the third chamfer extends in thefirst direction different from a third direction in which the firstchamfer extends from the surface of the substrate.
 13. The substratestructure of claim 1, wherein the surfaces of the first and secondchamfers each have a straight face, a convexed or concaved arc face.